This invention relates to bicycle brakes, and includes a brake having a finned brake shoe with a pad of frictional material secured thereto, the fins on the shoe provide improved dissipation of heat from the brake to atmosphere.
In the prior art, bicycle brakes are usually of the caliper type and are mounted on opposite sides of the rim of the wheel of the bicycle and are energized substantially perpendicular to the plane of the wheel into engagement with the rim thereof to slow or stop forward motion of the bicycle.
Additionally, prior art bicycle brakes typically comprise a block of friction material bonded or otherwise secured to a backing plate or support, and when braking effort is applied, the brake becomes heated, thus losing a considerable amount of its braking effectiveness. Notwithstanding this, cooling of prior art bicycle brakes is generally not provided for. However, a severe stop from high speed or down a long steep hill, after the friction material of the brake pad has heated up excessively may require more force than such a stop requires using a cooled brake. A severe stop from high speed or down a long steep hill, after the friction material of the brake pad has heated up excessively may not be as effective for a given amount of hand pressure on the brake lever because the coefficient of friction falls off rapidly as the friction material heats up. Thus, when long downhill grades are encountered, or under race conditions, when brakes are likely to become heated due to hard use, it is most important to reduce maximum friction material temperatures in order to maintain effective braking action.
Additionally, many known brake shoes comprise a metal housing into which is pushed or inserted a block of friction material. However, such housings do not efficiently transfer heat because of only a casual of intermittent contact between the shoe and the housing. Thus, the heat transfer rate is low due to the poor thermal contact between the shoe and the housing. Therefore, it is very important that the shoe, or housing, have a good heat transfer path to the atmosphere to at least partially compensate for the poor thermal contact between the friction material and the housing.
In the present invention, a finned shoe promotes a transfer of heat from the brake to atmosphere which is improved over the heat transfer from known brakes, and thus the effectiveness of the brake is maintained even under severe usage.